Balanced valve.



W. P; GOULD.

BALANCED VALVE.-

' IIIIIIIIIIIIIIIIIIIIIIII 9 1,014,592, Patented Jan. 9, 1912.

ocmwn co.. WASHINGTON. n. c

' UNITED STATES PATENT OFFICE, j

WILLIAM F. GOULD, OF DES MOINES, IOWA,

BALANCED VALVE.

Specification of Letters Patent.

To all whom it may concern:

Be it known that I, WILLIAM F. GOULD, a citizen of the United States,residing at Des Moines, in the county of Polk and State of Iowa, haveinvented a certain new and useful Balanced Valve, of which the followingis a specification.

My invention relates to that class of valves in which a valve cover isemployed to prevent pressure of the steam chest steam upon the outersurface'of the valve.

. The object of my invention is to provide a valve of the classknown asslide valves, with means whereby the valve will be yieldingly held bysteam pressure from the steam chest against the valve seat at such timesduring the stroke of the valve as there is an outward pressure upon theinner surface of the valve caused by the induction port pressure of theengine.

7 'My invention consists in the construction, arrangement, andcombination of thevarious parts of the device whereby the objectscontemplated are attained, as hereinafter more fully set forth, pointedout in my claims,'and illustrated in the accompanying drawings, inwhich-' Figure 1 shows a vertical, central sectional view of a portionof a valve seat with the induction and exhaust ports therein, a

steam chest, a slide valve, and a valve cover embodying my invention.Fig. 2 shows a Fig. 1, and Fig. 3 shows a view similar to Fig. 1 withthe valve in a different position, the ends of the steam chest and valve1 cover being removed.

Referring to the accompanying drawings, I have used the referencenumeral 10 to indicate the valve seat in which there are two inductionports 11 and an exhaust port- 12. The steam chest is indicated by thenumeral 13 and is provided with a steam supply pipe 14. Within the steamchest is I a segmental valve cover 15 normally held downwardly by meansof the set-screws l6. Arranged between the seat and the steam chest is aslide valve 17 of the ordinary construction comprising two similar endportions each havlng on its under surface a seating portion 18 torest'on the valve seat, and a segmental body portion provided with twoparallel grooves in its outer surface and with two packing bars 19 insaid grooves, said packing bars being spaced deemed unnecessary.

the valve. The valve is also provided with two sides 20 connecting thevalve ends, each of said sides being provided with a Application filedMay 19, 1909. Serial No. 496,894.

packing bar 21 to engage the inner packing bars 19 on the valve ends, asshown 1n Fig. 1.

The parts before described are substan-j tially similar to valves now ingeneral use and said parts operate in the ordinary man nor of valves ofthis class, hence a detailed description of the operation of sameis Ihave provided simple and. inexpensive means for provldlng a steampressure upon the outer surface of the valve, with steam:

from the steam chest, that will be applied to the outer surfaceof thevalve at the same time that the outward pressure upon the valve isapplied from the induction port, which steam pressure upon the outersurface of the valve will be relieved at the same time that the portressure is relieved and will be also applie at the same time that theport pressure is applied'on'both ends ofthe valve; that is'to say, whenone end of the valve is being subjected to out- :ward port pressure, itwill, at the same sectional view of same on the line 22 of 2 time, besub ected to an inward steam pres-I 5 sure by" steam from the chest andthe other end. of the valve will be relieved from said steampressure'from the steam chest.

My improved means for admitting steam I from the steam chest to thesteam chambers on the outer surface of the valve comprises a steamchamber 22 formed in the valve cover and provided with two passageways23 and 24 both leading to the under surface of the valve cover and beingspaced apart from each other. The distance to which said passageways 23and 24 are spaced apart is preferably slightlyless than the distancebetween the packing bars 19 on one end of the valve, and the spacebetween said passageways 23 and 24 is somewhat greater than the width ofone of the packing bars.

Said steam passageways are arranged in the valve cover substant ally 1nthe manner shown in Fig. 1, so that they will co-act with the valve andthe packing bars thereon in admitting steam to the steam chamber beiiotween the packing bars 19 and discharging it from said steam chamber inthe manner hereinafter described. It is to be understood in thisconnectiom that there are two kinds of port pressure against which thevalve must be balanced. First, when the end of the valve that isadjacent to the induction port through which steam is being delivered tothe cylinder is in position partly covering the induction port, the livesteam within the induction port will press outwardly upon that part ofthe valve that overlaps the induction port. This kind of steam pressureoutwardly on the valve, l have termed hereinafter as live steampressure; second, when the piston approaches one end of the cylinder, itwill compress the steam therein and force it out through the adjacentinduction port, and this compressed steam will exertan outward pressureupon the part of the valve that overlaps said port,

and for convenience in the description, I have termed this kind of steampressure as compressed steam pressure.

Referring to Fig. 1 of the drawings and assuming that the valve ismoving toward the left, it is obvious that there is no port pressure onthe right end of the valve from the adjacent induction port, and,therefore, there is no need for applying pressure to the outer surfaceof the, valve. Assuming, however, that the valve moves toward the left aslight distance, it is obvious that the passage-way 24 will be opened,to permit live steam from the steam chest to enter the steam chamber onthe outer surface of the valve, and as the valve moves a slight distancefarther toward the left, the steam from the steam chest will enter theadjacent induction port. This will cause a pressure upon the undersurface of the valve in a direction away from the valve seat, whichpressure will be counter-balanced by the live steam pressure within thesteam chamber on the outer surface of the valve. As soon as the valvemoves far enough to the left so that there will be no outward steampressure upon it from the induction port, then the right one of thepacking bars 19 will move beyond the passage-way 23 topreveut furtheradmission of steam into said steam chamber from the steam chest. Afterthe supply of steam from the chest to the .-team chamber between thepacking bars 19 is cut off in the manner described, the pressure of thesteam in said steam chamber on the outer surface of the valve willgradually diminish substantially in proportion to the decreased pressureupon the under surface of the valve as the valve moves away from theinduction port. In Fig. 3 of the drawings, the valve is shown inposition where it substantially uncovers the right induction port andwhen in said position, the steam chamber between the packing bars 19 issome distance away from the passage-way to supply steam to it from thesteam ches Referring again to Fig. l of the drawings, particularly tothe'left end of the valve, and assuming that the valve is moving towardthe left, it is obvious that the valve has just .cut off .the flow ofsteam from the steam chest into the left induction port and that,therefore, the pressure within the left induction port is substantiallyequal to that within the steam chest, hence the passage: way into the:steam chamber on the outer surface of the valve is open to balance thepressure upon the valve. As the valve travels toward the lefta shortdistance, it will soon cut off the passage-way 23. This will occur atabout the time when the left end of the valve passes beyond the leftinduction port far enough to permit the exhaust to commence, and thepressure upon the outer surface of the valve will gradually decrease bymeans of the condensation and leakage around the packing bars as theleft end of the valve passes beyond the left induction port, and by thetime, the left end of the valve reaches the position shown inFig. 3, atthe right of thefigure, any steam left in the steam chamber on the outersurface of the valve will also, pass into the exhaust. Then as the leftend of the valve begins to move toward the right, the piston will beginto approach the adjacent end of the cylinder and it will begin tocompress the steam in the left end of the cylinder, thus causing apressure outwardly upon the valve. The tlme when this compressionpressure is greatest is just before the left end of the valve moves toposition for commencing to admit steam into the leftsteam inductionor't, and it is at the same time that the eft passage-way in the valvecover admits steam into the steam chamber on the back of the Valve. Inother words, each end of a valve is subjected first to an outwardcompression steam pressure and then immediately following'same, it issubjected to an outward steam pressure by live steam from the steamchest, which continues for a greater part ofits stroke than does thecompression steam pressure. The passageways in the valve cover are soarranged that they will admit steam from the steam chest to the steamchamber between the packing bars when said compression steam pressurebegins and will continue to admit steam until after the live steampressure begins, and said steam pressure upon the outer surface of thevalve will be cut off before the valveun covers the induction port thatis admitting live steam. However, the pressure of-steam within thechamber between the packing bars will gradually diminish by leakage andcondensation during the time that the induction port is being uncoveredand then when the induction port is wholly uncovered as shown to theleft in Fig. 3, any steam remaining in the chamber between thepackingbars may pass into the exhaust. It is obvious that there ispractically no steam chest pressure upon the valve tending to hold ittoward its seat because the valve cover prevents same,.and the valvewould be perfectly balanced by means of the cover alone if it were notfor the port pressure.

By my improved arrangement, I' have provided for admitting steam fromthe steam chest to the chambers between the packing bars on the valve atsuch times and in such quantities as to approximately counter-balancethe port pressure upon the under surface of the valve during the timeswhen said pressure exists.

I claim as my invention- 1. The combination of a steam chest, a valveseat having induction ports, a slide valve on the valve seat, a steamchamber fbrmed on the outer surface of the slide valve and closed fromcommunication with induction ports at all positions of the slide valve,a valve'cover' within the steam chest being provided with a passagewaydesigned to admit steam from the steam chest into said steam chamberduring a portion of the valve stroke.

2. The combination of a steam chest, a valve seat having inductionports, a slide valve on the valve seat having asteam chamber on theouter surface of each end, said chambers being closed from communicationwith induction ports at all positions of the slide valve, a valve coverbeing provided with two passageways, each being designed to admit steamfrom the steam chest to the steam chamber on the adjacent end of thevalve during a part of the valve stroke.

3. The combination of a steam chest, a valve seat having inductionports, a slide valve on the valve seat, a steam chamber formed on theouter surface of the slide valve and closed from communication withinduction ports at all positions, a valve cover within the steam chestbeing provided with a passageway designed to admit steam from the steamchest into said steam chamber during a portion of the valve stroke, andalso being designed to permit steam to exhaust from the steam chamberduring a part of the valve stroke.

4:. The combination of a steam chest, a valve seat having inductionports, a slide valve on the valve seat having a steam chamber on theouter surface of each end, said chambers being closed from communicationwith induction ports at all positions of the valve, a valve cover beingprovided with two passageways, each being designed to admit steam fromthe steam chest to the steam toexhau'st from the chambers on the ends ofthe valve during a part of the valve stroke.

5. The combination of a steam chest, a slide valve therein having asteam chamber on its outer surface, a valve cover being provided with asteam ch amber having passageways at its ends leading to the surface ofthe valve cover adjacent to the valve,'said passage-ways being spacedapart slightly less than thewidth of the steam chamber on the outersurface of the valve.

6. The combination of a steam chest, a slide'valve therein havinggrooves on its outer surface, packing bars in'said grooves to'forma'steam chamber between them, a valve cover being provided with a "steamchamber having passage-ways at its ends leading to the surface of thevalve coveradjacent to the valve, said passage-ways being of less widththan the width of the packing bars so that the packing bars will cut offeach passage Way when in position adjacent to it.

7. The combination of a steam chest, a slide valve therein havinggrooves on its outer. surface, packing bars in said grooves to'form asteam chamber between them, a valve cover being provided with a steamchamber having passage-ways at its ends leading to the surface of thevalve cover adjacent to the valve, said passage-ways bei'ngofless widththan the'width of thepacking bars so that the packing bars will cut offeach passage Way when in position adjacent to it, and said passage-waysin the valve cover being spaced apart from each other slightly less thanthe distance between the two packing bars.

8. The combination of a steam chest, a slide valve therein having asteam chamber on its outer surface, a valve cover, a steam chambertherein having passage-ways at its ends leading to the surface of thevalve cover adjacent to the valve, a valve seat having an inductionport, said parts being so arranged'that when the valve is in position topartially uncover the induction port to permit steam from the chest toenter the induc tion port, the steam chamber on the outer surface of thevalve will be in such position that steam from the chest may enter oneof said passage-ways and discharge through the other into the steamchamber on the outer surface of the valve.

9. The combination of a valve seat having an induction port therein, avalve mounted on the seat, two packing bars spaced apart on the valve toform a steam chamber between them, a valve cover in engagement with thepacking bars, a steam chest, said being so arranged relative to theinduction port that steam will be admitted from the steam chest into thesteam chamber on the outer surface. of the valve during that portion vofthe valve stroke in which there is a compression steam pressure on theunder surface of the valve and also when there is a live steam pressureon the under surface of the valve.

10. The combination of a valve seat having an induction port therein, avalve mounted on the seat, two packing bars spaced apart on the valve toform a steam chamber between them, a valve cover in engagement with thepacking bars, a steam chest, said valve cover being provided with asteam chamber having passage-Ways at its ends leading to the surface ofthe valve cover adjacent to the valve, and said passage- Ways being soarranged relative to the induction port that steam will be admitted fromthe steam chest into the steam chamber on the outer surface of the valveduring that portion of the valve stroke in which there is a compressionsteam pressure on the under surface of the valve and also when there isa live steam pressure on the under surface of the valve, saidpassage-ways being also so arranged that they will permit steam toexhaust from the chamber between the packing bars during that portion ofthe valve stroke in which the exhaust is passing outwardly through'theinduction port.

tions and open at its center, two packing bars at eachend of the valvespaced apart to form steam chambers between them, a valve cover, a steamchest, said valve cover being provided with two steam chambers eachhaving two passage-ways leading to the surface of the valve coveradjacent to the valve, and said passage-ways being so arranged as toadmit steam from the steam chest to the adjacent steagn chamber on theouter surface of the valve during that portion of the valve movement inwhich there is a compression steam pressure in the adjacent inductionport upon the valve and during the time that there is a live steampressure from the induction port upon the valve, said passage-ways beingalso arranged to permit the steam in said steam chambe between thepacking bars to exhaust into the space between the ends of the valveduring that portion of the valve stroke in which the induction port isin communication with the exhaust port.

Des Moines, Iowa, April 16, 1909.

WILLIAM F. GOULD.

Witnesses:

N. M. TAYLOR, M. B. GOLDIZEN.

copies'of this patent may be obtained for five cents each, by addressingthe "Commissioner of Patents,

, Washington, D. 0.

